System for replacing environmental fluid in boreholes and other fluid-confining means

ABSTRACT

A system for replacing environmental fluid in boreholes and similar fluid-confining structures for photographic and similar purposes. The system includes a cylinder having opposite ends, a transparent fluid in the cylinder, a piston in the cylinder adjacent to one end of the cylinder urged toward the opposite end, remotely operable flow control valve structure confining the transparent fluid within the cylinder and thereby releasably restraining the piston adjacent to said one end, a conduit extended from said opposite end of the cylinder to an area to be photographed to deliver the transparent fluid thereto upon release of the piston, and a conduit extended from said one end of the cylinder to the area to be photographed to draw environmental fluid from said area into the cylinder for replacement purposes.

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M "i a 2,812,697 11/1957 Laval...t.........i..............

2,940,370 6/1960 Yan dell.........i.........i....

Primary ExaminerSamuel S. Matthews Assistant ExaminerMichael D. HarrisAttorney-Huebner and Worrel ABSTRACT: A system for replacingenvironmental fluid in boreholes and similar fluid-confining structuresfor graphic and similar purposes. The system includes a c havingopposite ends, a transparent fluid in the cyli piston in the cylinderadjacent to one end of the cylinder urged toward the opposite end,remotely operable flow control valve structure confining the transparentfluid within the cylinder and thereby releasably restraining the pistonadjacent to said one end, a conduit extended from said opposite end ofthe cylinder to an area to be photographed to deliver the transparentfluid thereto upon release of the piston, and a conduit extended fromsaid one end of the cylinder to the area to be photographed to drawenvironmental fluid from said area into the cylinder for replacementpurposes.

Wayne L. Sayer Bakersfield, Calif. 747,969 July 26, 1968 UndergroundSurveys Corporation References Cited UNITED STATES PATENTS 6/1957Laval..........................

v lllvu U IIGLCD l l [72] Inventor [21] Appl, No.

[22] Filed [45] Patented Aug. 3, 1971 [73] Assignee [54] SYSTEM FORREPLACING ENVIRONMENTAL FLUID 1N BOREl-IOLES AND OTHER FLU CONFININGMEANS 8 Claims, 2 Drawing Figs.

Int.

PATENTEU AUG 3m:

w m @l P ll-47 as IN VE N 70/? A 7TORNE V S WA YNE L. SAVER g I x g ASYSTEM FOR REPLACING ENVIRONMENTAL FLUID IN BOREHOLES AND OTHERFLUID-CONFINING MEANS BACKGROUND OF THE INVENTION The present inventionrelates to a system for replacing environmental fluid in boreholes andthe like as required for borehole photography and as performed byapparatus of the type shown and described in US. Pat. Nos. 2,677,996 and2,982,191. It is to be understood that the term photography," asemployed herein, is intended to include the production of a viewableimage whether of the light-sensitive chemical, electronic, or other formand whether such image is of relatively permanent or transientcharacter.

The extreme environmental problems encountered in borehole photographyare described in the aforementioned patents. Borehole cameras aredescribed therein which are adapted to be lowered into a well, forexample, to take a photograph therein. The cameras are of particularsignificance in their ability to take photographs even below the surfaceof opaque or translucent liquids in the well. This is accomplished byreplacing the liquid in the well through which satisfactory photographscannot be taken with a liquid or other fluid medium which is opticallytransparent and through which satisfactory photographs can be taken, thetransparent fluid having a different specific gravity from that of thewell fluid. The cameras described in the patents are suited to thepurpose but the fluid displacement mechanisms thereof are subject tocertain difficulties which the present invention seeks to overcome. Ithas been difficult to supply adequate electrical energy for dependableoperation through lengthy conductors required to reach remote locations.High pressures and temperature encountered in extremely deep wells andthe like have impaired proper operation.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an improved system for replacing environmental fluid inboreholes and other fluid-confining means.

Another object is to provide an improved photographic apparatus whichincludes a fluid replacement system and serves the same general purposesas the apparatus of the aforementioned patents.

Another object is to provide a photographic apparatus having a fluidreplacement system capable of withstanding high environmental pressures.

Another object is to provide a fluid replacement system for use with aborehole camera which is of simple and economical construction.

Another object is to provide a remotely operable fluid replacementsystem that can be controlled by a single electrical conductor.

Another object is to provide a remotely operable fluid replacementsystem which has a self-contained energy source for actuating the fluidreplacement operation.

Another object is to provide such an energy source in a fluidreplacement system which is unimpaired by high environmental pressuresand temperatures as are frequently encountered in borehole photography.

Another object is to extend the distances of which fluid replacementsystems can be remotely actuated.

Another object is to provide a fluid replacement system which operatesin a reliable and facile manner and is excellently suited for itsintended purpose.

Further objects and advantages will become apparent in the subsequentdescription of the illustrative embodiment shown in the drawing.

BRIEF DESCRIPTION OF DRAWING FIG. 1 is a foreshortened longitudinalvertical section through a borehole photographic apparatus embodying thefluid replacement system of the present invention.

FIG. 2 is a fragmentary vertical longitudinal vertical section of theborehole photographic apparatus showing a succeeding relationship of theparts thereof during operation.

DESCRIPTION OF EMBODIMENT Referring in greater detail to the drawing,there is illustrated in FIG. 1 a borehole photographic apparatus 10,including a borehole camera 112 and a fluid replacement system 14, showndisposed in a borehole casing 16. The system 14 includes an innertubular housing or cylinder 18 within which a piston 20 is freelyslidable, the piston being fitted to the housing with a sliding sealingfit. Obviously, O-rings, not shown, may be used in circumscribingrelation to the piston to effect such a seal. Adjacent to one end of thehousing 18 is an end wall or plug 22 which is in facing relation to oneend 24 of the piston 20. The end wall and the piston end and the portionof the housing 18 therebetween define a chamber 26 for containing asupply of optically transparent or clear fluid 28. The end wall 22 isprovided with a valve 30 operated by a solenoid 32 controlled from aboveground by a single conductor in an electrical control cable 36. This isaccomplished by connecting the operating solenoid to the conductor andto ground. Whenever the conductor is energized the solenoid is actuatedto open the valve. Whenever the conductor is deenergized, the solenoidis deactivated and the valve closes. The cable may also containconductors for the remote control of the sequencing of the camera 12from above ground or a single control conductor may be utilized foroperating the solenoid and initiating a sequence of operation ofthecamera, as operational circumstances may suggest.

The camera 12 is mounted within the housing 18 below the wall 22 and inspaced relation thereto to provide a passageway 38 through which theclear fluid 28 can pass to the exterior of the housing for displacingborehole liquid 40 therebelow. The lower end of the housing 18 ispreferably equipped with an annular deflecting lip 42 for causing theclear fluid to be deflected across a pair of stereopticon windows 44forming part of the camera 12 for the purpose of flushing and cleaningthe same. An electric lamp 46 or other suitable source ofillumination isoperatively associated with the camera 12 and wiring 47 is provided fordelivering electrical power to the lamp.

The lamp 46 is mounted on a conduit 48 having at its lower end an openintake end 50 disposed below the lamp 46 in a position such that liquidor fluid drawn into the intake end is caused to flow across the lamp forflushing and cleaning the same. The conduit 48 is in communication witha cylindrical passageway 52 defined by a double wall constructionresulting from concentrically arranging an outer tubular housing 54around the housing 18. The housing 54 has the lower end thereof securedto the housing 18, as by welding or the like, and the upper end thereofclosed off by an end cap 56 to which a supporting bracket 58 is fixed.

The end cap 56 defines one end of receiving chamber 60 which is incommunication with the passageway 52, the other end of the chamber beingdefined by an end 62 of the piston 20. A ring 64 of suitable material issecured at the upper end of the housing 18 for engaging the piston end62 and limiting the extent of sliding movement of the piston in onedirection, as shown in FIG. I, travel of the piston in the oppositedirection being limited by engagement of the piston end 24 with the endwall 22, as shown in FIG. 2. The end cap 56 is provided with a releasevalve 66 which is opened to permit the escape of trapped air and/orliquid during movement of the piston into engagement with the limit ring64 for filling the chamber 26 with the clear fluid 28.

The lower ends of the housings l8 and 54 have secured thereto pairs ofrings or cup packers 68 and 70 for engaging the casing wall andeffecting a seal therewith. The rings are made of any suitable flexiblematerial and are arcuately formed to curve downwardly so that pressureagainst the lower sides thereof forces them into tighter engagement withthe casing wall. Such packers are well known in the art.

The piston is formed or filled with a material having a high specificgravity, for example, lead, for gravitationally pressurizing the fluid28. Also, the supply chamber 26 is made sufficiently large to providefor displacing the necessary volume of the borehole liquid, preferablysufficient to perform the replacement function at each of a plurality oflocations in the borehole. To this end, the control of the valve 30 issequenced to permit the necessary amount of the fluid 28 to flow out andreplace the borehole liquid below the apparatus, after which the valveis closed.

The camera 12 is then sequenced from above ground for taking photographsor otherwise investigating the borehole. The sequencing of the cameramay also be accomplished automatically by an activation system includingwires 72 and a switch 74 which is actuated by movement of the piston end24 into engagement with the end wall 22. It is understood, of course,that the cable 36 and the wires 47 are suitably covered for protectionagainst the environmental conditions present in a borehole and that theviewing device 12 is similarly conditioned, preferably by being fluidfilled.

A suspension cable 76 is attached to the bracket 58 and to winchingapparatus above ground, not shown, for raising and lowering theapparatus.

OPERATION The operation of the device of the present invention isbelieved to be clearly apparent and is briefly summarized at this point.In preparation for the descent into a borehole, the apparatus isinverted to cause the piston to move gravitationally into contact withthe limit ring 64, the relief valve 66 being in the open condition forpermitting the escape of air and/or liquid from the chamber 60 whichbecomes progressively smaller with movement of the piston to the limitring. In the meantime, the chamber 26 becomes progressively larger andis filled with the clear fluid 28 by passing the fluid through the valve30 which is placed in open condition for the purpose. After the chamber26 has been filled, valve 30 is closed and the apparatus is raised toerect operating position by means of the suspension cable 76 and thewinching apparatus, not shown. With the valve 66 closed and the cable 36suitably connected to the control mechanisms above ground, the apparatus10 is lowered into the borehole casing 16 and allowed to descend to thelocation where it is desired to view or image conditions within theborehole. During descent, the borehole liquid 40 enters the intake end50 of the conduit 48. As the pressure increases with greater depth, thewell fluid is forced into the passageway 52 and eventually into thereceiving chamber 60. Under such conditions, the pressure of theborehole liquid at the viewing depth is substantially equally effectiveon both ends of the piston and the full weight of the piston isavailable for pressurizing the clear fluid 28 and forcing it out toreplace the borehole liquid. lf desired, the conduit 48 and passageway52 are also filled with the clear fluid so that there is no air trappedin the system. This is particularly desirable where extreme pressuresare to be encountered.

Preferably, the apparatus is permitted to descent a slight distance pastthe viewing location and then pulled up slightly in order that the cuppackers 68 and 70 assume the downwardly curved positions shown in FIGS.1 and 2 for obtaining an effective seal with the interior of the casing.The aboveground controls are then operated to open the valve 30 for apredetermined amount of time and then close it. With the valve 30opened, the fluid 28 in chamber 26 flows through the valve in responseto the pressure exerted thereon by the weight of the piston 20. Thefluid flowing from the chamber passes through the passageway 38 aroundthe viewing device l2 and across the windows 44 thereof for displacingthe borehole liquid 40 adjacent thereto until sufficient liquid isforced into the intake end 50 of the conduit 4%] and the passageway 52,such liquid eventually finding its way into the receiving chamber 60which has been enlarged by downward movement of the piston. The viewingdevice is then sequenced for taking photographs or for viewing theborehole through the transparent optical fluid immediately therebelow.The apparatus is then moved to another location in the borehole and theprocess of displacing the borehole liquid with clear optical fluid andviewing therethrough is repeated until the piston engages the end wall22. At this time, the switch 74 is closed and the viewing device isautomatically sequenced, which condition may be indicated above groundby an audio or visual signal or both, after which the apparatus iswithdrawn from the borehole.

The fluid replacement system of the present invention provides its ownsource of energy for remote operation. The energy is dependablyavailable and uninfluenced by high pressures or temperatures. Theoperation of the system is dependably and easily initiated andinterrupted through a single conductor from even extremely remotelocations. lts simplicity enables it to be economically produced and toattain absolute reliability.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices and apparatus.

Having described my invention, what l claim as new and desired to secureby Letters Patent is:

l. A system for replacing environmental fluids disposed within boreholescomprising:

A. a substantially sealed cylinder having opposite ends;

B. a displaceable piston seated within said cylinder adjacent to one endthereof continuously urged in displacement toward the other end of thecylinder, including a pair of coaxially related faces oppositely spacedfrom the ends of the cylinder and defining therewithin a first and asecond coaxially related chamber;

C. a transparent fluid at a first pressure substantially filling saidfirst chamber;

D. a fluid discharge conduit communicating with said said first chamberfor conducting fluid from said cylinder;

E. an environmental fluid at a second pressure substantially fillingsaid second chamber;

F. displacement initiating means for initiating displacement of thepiston comprising a selectively operable flow control valve seated insaid discharge conduit adapted to be opened for accommodating adischarge of said fluid from said cylinder; and

G. a substantially unobstructed fluid intake conduit for extending froma body of environmental fluid to the second chamber for continuouslymaintaining the second chamber in direct communication with the body ofenvironmental fluid for thus maintaining the pressure of theenvironmental fluid substantially filling the second chambersubstantially equal to the pressure of the body of environmental fluid,whereby the transparent fluid is discharged through said dischargeopening and the environmental fluid is delivered to the second chamberas the piston is displaced within the cylinder.

2. The system of claim 1 wherein the cylinder is by its weight urged indisplacement.

3. A system for replacing environmental fluid in boreholes and the likecomprising an elongated cylinder having an upper and a lower end, aweighted piston mounted in the cylinder for reciprocal movement betweenthe ends, whereby the cylinder is divided into an upper and a lowerchamber each having an axial dimension dictated by the position of thepiston relative to said ends, a substantially transparent fluidsubstantially filling the lower chamber of the cylinder, releasablemeans restraining said piston adjacent to the upper end of the cylinder,an outlet conduit connected to the lower chamber having an open endexternally of the cylinder beneath the lower end thereof foraccommodating a discharge of the substantially transparent fluid fromthe cylinder, and a substantially unobstructed intake conduit in directcommunication with the upper chamber and having an open end externallyof the cylinder to be immersed within a pressurized body ofenvironmental fluid whereby said upper chamber is brought into directcommunication with said body of environmental fluid for conductingenvironmental fluid to the upper chamber for replacing the substantiallytransparent fluid as it is discharged from the cylinder.

4. The system of claim 3 in which said fluid within said lower chamber,the body of environmental fluid, and said environmental fluid withinsaid upper chamber are subjected to substantially common pressure,whereby the' weight of the piston establishes a force of a magnitudesufficient for displacing the piston.

5. The system of claim 3 in which the releasable means comprises a valvemounted on the outlet conduit.

6. The system of claim 5 including electrical means operably connectedto the valve controllable remotely from the valve to open and to closeit whereby discharge of fluid from the cylinder can be regulated tooccur in spaced increments at different positions in the borehole.

7. The system of claim 5 in which the open end of the outlet conduit isdownwardly spaced from the open end of the intake conduit.

8. A system for replacing environmental fluid in boreholes and the likecomprising:

A a housing adapted to, be immersed in a pressurized body ofenvironmental fluid including an elongated cylinder having an upper anda lower end;

B.'a weighted piston mounted in the cylinder for reciprocalfluid-discharging movement between the ends thereof, whereby thecylinder is divided into an upper and a lower chamber each having avariable axial dimension dictated by the position of the piston relativeto said ends;

C. a substantially transparent fluid substantially filling the lowerchamber of the cylinder;

D. releasable means restraining said piston adjacent to the upper end ofthe cylinder;

E. an outlet conduit connected to the lower chamber having an open endexternally of the cylinder beneath the lower end thereof foraccommodating a discharge of the substantially transparent fluid fromthe cylinder as the piston is moved toward the lower end of thecylinder; and

F. means establishing a substantially direct communication between theupper chamber and said body of environmental fluid for accommodating apassage of environmental fluid from said pressurized body to the upperchamber for replacing the substantially transparent fluid in thecylinder as the piston is moved toward the lower end of the cylinder.

1. A system for replacing environmental fluids disposed within boreholescomprising: A. a substantially sealed cylinder having opposite ends; B.a displaceable piston seated within said cylinder adjacent to one endthereof continuously urged in displacement toward the other end of thecylinder, including a pair of coaxially related faces oppositely spacedfrom the ends of the cylinder and defining therewithin a first and asecond coaxially related chamber; C. a transparent fluid at a firstpressure substantially filling said first chamber; D. a fluid dischargeconduit communicating with said said first chamber for conducting fluidfrom said cylinder; E. an environmental fluid at a second pressuresubstantially filling said second chamber; F. displacement initiatingmeans for initiating displacement of the piston comprising a selectivelyoperable flow control valve seated in said discharge conduit adapted tobe opened for accommodating a discharge of said fluid from saidcylinder; and G. a substantially unobstructed fluid intake conduit forextending from a body of environmental fluid to the second chamber forcontinuously maintaining the second chamber in direct communication withthe body of environmenTal fluid for thus maintaining the pressure of theenvironmental fluid substantially filling the second chambersubstantially equal to the pressure of the body of environmental fluid,whereby the transparent fluid is discharged through said dischargeopening and the environmental fluid is delivered to the second chamberas the piston is displaced within the cylinder.
 2. The system of claim 1wherein the cylinder is by its weight urged in displacement.
 3. A systemfor replacing environmental fluid in boreholes and the like comprisingan elongated cylinder having an upper and a lower end, a weighted pistonmounted in the cylinder for reciprocal movement between the ends,whereby the cylinder is divided into an upper and a lower chamber eachhaving an axial dimension dictated by the position of the pistonrelative to said ends, a substantially transparent fluid substantiallyfilling the lower chamber of the cylinder, releasable means restrainingsaid piston adjacent to the upper end of the cylinder, an outlet conduitconnected to the lower chamber having an open end externally of thecylinder beneath the lower end thereof for accommodating a discharge ofthe substantially transparent fluid from the cylinder, and asubstantially unobstructed intake conduit in direct communication withthe upper chamber and having an open end externally of the cylinder tobe immersed within a pressurized body of environmental fluid wherebysaid upper chamber is brought into direct communication with said bodyof environmental fluid for conducting environmental fluid to the upperchamber for replacing the substantially transparent fluid as it isdischarged from the cylinder.
 4. The system of claim 3 in which saidfluid within said lower chamber, the body of environmental fluid, andsaid environmental fluid within said upper chamber are subjected tosubstantially common pressure, whereby the weight of the pistonestablishes a force of a magnitude sufficient for displacing the piston.5. The system of claim 3 in which the releasable means comprises a valvemounted on the outlet conduit.
 6. The system of claim 5 includingelectrical means operably connected to the valve controllable remotelyfrom the valve to open and to close it whereby discharge of fluid fromthe cylinder can be regulated to occur in spaced increments at differentpositions in the borehole.
 7. The system of claim 5 in which the openend of the outlet conduit is downwardly spaced from the open end of theintake conduit.
 8. A system for replacing environmental fluid inboreholes and the like comprising: A a housing adapted to be immersed ina pressurized body of environmental fluid including an elongatedcylinder having an upper and a lower end; B. a weighted piston mountedin the cylinder for reciprocal fluid-discharging movement between theends thereof, whereby the cylinder is divided into an upper and a lowerchamber each having a variable axial dimension dictated by the positionof the piston relative to said ends; C. a substantially transparentfluid substantially filling the lower chamber of the cylinder; D.releasable means restraining said piston adjacent to the upper end ofthe cylinder; E. an outlet conduit connected to the lower chamber havingan open end externally of the cylinder beneath the lower end thereof foraccommodating a discharge of the substantially transparent fluid fromthe cylinder as the piston is moved toward the lower end of thecylinder; and F. means establishing a substantially direct communicationbetween the upper chamber and said body of environmental fluid foraccommodating a passage of environmental fluid from said pressurizedbody to the upper chamber for replacing the substantially transparentfluid in the cylinder as the piston is moved toward the lower end of thecylinder.